JPH01127798A - Propulsion reaction receiving method in method of cast-in-place shield construction - Google Patents

Abstract

PURPOSE: To increase friction resistance force by feeding fluid under pressure into a tube in a space formed by ringlike inner form taper plates to press the taper plates and pressing a form against a lining by component force. CONSTITUTION: A taper plate 3 part narrowing and squeezing a plate member 2 of a form toward an inner side and vertical plate 4 part for joint are provided alternately or by placing a plate 3 at the center to form an inner form 1. Furthermore, after inserting a flexible and tough tube 7 capable of inflating and deflating into a ridge-shaped box 6 of adjacent plates 3, concrete is placed into a space 14 surrounded by a shield tail 10, the from 1, and a press ring 13 so that a shield machine 13 advances and digs by a shield jack 12 while pressurizing the concrete by a press jack 11. After producing the concrete, fluid is fed into the tube 7 to press the plate 3 by inflated inflation pressure, and the form 1 is uniformly pressed against a lining 15 by component force to increase friction resistance force. Consequently, tensile stress of the lining 15 becomes uniform, and it is possible to prevent a crack due to the concentration of local tensile force.

Description

[Detailed description of the invention] [Industrial application field]

This invention secures the propulsion reaction force by uniformly pressing the inner frame against the lining using fluid pressure in the lining concrete part that has developed the required strength, increasing the vessel resistance force.

[Conventional technology]

Conventionally, the propulsion reaction force of the cast-in-place shield construction method is transmitted to the concrete through the formwork, but the normal friction force between the formwork and concrete is not sufficient to receive the propulsion reaction force. I can't say it. Therefore, a method is used in which a protrusion is provided on the outside of the formwork and the propulsion reaction force is secured by the shear paper resistance of the protrusion and the concrete, but this method requires time and labor for post-finishing and is not economical. It's something that doesn't exist.

[Problems to be solved by the invention]

Even if the propulsion reaction force of the cast-in-place shield construction method is transferred to the concrete through the formwork and the propulsion reaction force is removed, the normal abrasion resistance of the formwork and concrete is not sufficient to absorb the propulsion reaction force. This is an invention that attempts to solve a problem that cannot be solved.

[Means to solve the problem]

After assembling the inner formwork into a ring shape with a tapered plate portion that is inserted inward, and inserting an expandable and deflated tube into the space formed by the adjacent tapered plates, the inner formwork, shield tail, and press are assembled. Concrete is poured into the space surrounded by the ring, and in the lining concrete part where the concrete has developed the required strength, fluid is pumped through the tube, and the expansion pressure of the tube presses the side plate, and the formwork is lining with the force. This problem was solved by uniformly increasing the pushing frictional resistance (frictional force, adhesion force) to ensure the propulsion reaction force against the shield jack installed at the tip of the inner formwork. .

[Effect]

A box surrounded by a tapered plate is formed at the connecting rod part of the inner formwork, a tube that can be expanded and contracted by fluid is inserted into the box, and the fluid is pumped into the tube so that the tapered plate is pushed by the expansion pressure of the tube. The formwork can be evenly pressed against the lining (concrete lining part) and immersed in it by that force, and I//! This increases the drag resistance (frictional force, adhesion force) and ensures the propulsion reaction force against the shield jack installed at the tip of the formwork.

【Example】

A joint plate (
4) The inner formwork (1) is formed by providing the tapered plates (3) alternately or in the center. The plate (4) has bolt holes (5) for connecting adjacent inner formworks (1).
). The inner formwork (1) formed in this way is placed inside the inner formwork (1) on which concrete has already been poured.
A flexible and strong tube (7) that can be expanded and contracted is assembled into a ring shape using bolts and nuts at the tip of 1) and placed inside a mountain-shaped box (6) formed by adjacent tapered plates (3). Insert the tube (7) into the box (6) and attach the support (8) from inside the tunnel to the box (6) using metal fittings.
This is to prevent it from popping out. A hose (9) connected to a fluid pump (not shown) such as a compressor or an oil pump is connected to the tube (7). After that, the space (■
4) Pour the concrete and pressurize the concrete with the press jack (11) while using the shield jack (12).
The shield machine (13) is propelled by the excavation. After that, when the covered concrete has developed the required strength, the bolts and nuts connecting the inner forms (1) connected in a ring shape are removed or loosened, and the fluid pump is driven to connect the tubes (7). Fluid delivery tube (7)
By expanding the tube (7) and pushing the taper plate (3) with the expansion pressure of the tube (7), the inner formwork (1) is uniformly pressed against the lining (concrete lining part (15)) by the force, creating a frictional resistance force. increase The frictional resistance force (frictional force, adhesion force) ensures a propulsion reaction force against the shield jack (12) installed at the tip of the inner formwork (0).

【effect】

Since the inner formwork can be pressed against the concrete with a uniform force, the tensile stress of the lining is also uniform, which prevents the occurrence of cracks due to local concentration of tensile force. It is expected that reliable frictional force and adhesion force will be developed, ensuring stability in excavation.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view of the entire shield, Fig. 2 is a cross-sectional view thereof, Fig. 3 is a cross-sectional view taken along the line m-m in Fig. 2, Fig. 4 is a cross-sectional view taken along the line ■-■ in Fig. 3, FIG. 5 shows a stress distribution diagram. Procedural amendment (method) also ^-・ Showa 63rd 3J11'f day ゛

Claims (1)

[Claims] (1) Assemble the inner formwork in a ring shape, which has a tapered plate portion that narrows inward, and insert an expandable and deflated tube into the space formed by the adjacent tapered plates. Concrete is cast in the space surrounded by the shield tail and press ring, and in the lining concrete part where the concrete has developed the required strength, fluid is pumped through the tube and the expansion pressure of the tube presses the taper plate, thereby forming the formwork. A method for receiving propulsion reaction force in the cast-in-place shield construction method, which is characterized in that the propulsion reaction force against the shield jack installed at the tip of the inner formwork is secured by uniformly pressing the lining against the lining using component force and increasing the frictional resistance force. .